Of course they have. There’s no easy way to completely stop flippers. If the next release is desirable enough (say an Islay 30yo), folk will join TWS just to get these bottles, and they won’t give a damn if they get chucked out again. They’ll have easily made the membership fee back on reselling them.
The best thing TWS could do to minimise flipping would be to limit it to one bottle per member.